* David Goulet ([email protected]) wrote:
> Improve protection to the variables where the uatomic_add_return() call
> does a volatile access and returns the value atomically incremented.
>
> Enclose that in two new functions, one for each id, which helps with the
> code semantic and brings a single call site for the value update making
> the code easier to scale and understand when adding contention to those
> variables.
>
> Signed-off-by: David Goulet <[email protected]>
This won't build on 32-bit architectures, due to lack of 64-bit atomic
ops.
Thanks,
Mathieu
> ---
> src/bin/lttng-relayd/lttng-relayd.h | 19 +++++++++++++++++++
> src/bin/lttng-relayd/main.c | 9 +++++----
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/src/bin/lttng-relayd/lttng-relayd.h
> b/src/bin/lttng-relayd/lttng-relayd.h
> index edd32d6..b2566a1 100644
> --- a/src/bin/lttng-relayd/lttng-relayd.h
> +++ b/src/bin/lttng-relayd/lttng-relayd.h
> @@ -23,6 +23,9 @@
> #include <urcu.h>
> #include <urcu/wfqueue.h>
>
> +extern uint64_t relayd_last_stream_id;
> +extern uint64_t relayd_last_session_id;
> +
> /*
> * Queue used to enqueue relay requests
> */
> @@ -81,4 +84,20 @@ struct relay_command {
> unsigned int version_check_done:1;
> };
>
> +/*
> + * Atomically increment the id and return the next stream id.
> + */
> +static inline uint64_t relayd_get_next_stream_id(void)
> +{
> + return (uint64_t) uatomic_add_return(&relayd_last_stream_id, 1);
> +}
> +
> +/*
> + * Atomically increment the id and return the next session id.
> + */
> +static inline uint64_t relayd_get_next_session_id(void)
> +{
> + return (uint64_t) uatomic_add_return(&relayd_last_session_id, 1);
> +}
> +
> #endif /* LTTNG_RELAYD_H */
> diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
> index 6627310..a042ce6 100644
> --- a/src/bin/lttng-relayd/main.c
> +++ b/src/bin/lttng-relayd/main.c
> @@ -82,8 +82,9 @@ static pthread_t listener_thread;
> static pthread_t dispatcher_thread;
> static pthread_t worker_thread;
>
> -static uint64_t last_relay_stream_id;
> -static uint64_t last_relay_session_id;
> +/* Declared extern in lttng-relayd.h */
> +uint64_t relayd_last_stream_id;
> +uint64_t relayd_last_session_id;
>
> /*
> * Relay command queue.
> @@ -968,7 +969,7 @@ int relay_create_session(struct lttcomm_relayd_hdr
> *recv_hdr,
> goto error;
> }
>
> - session->id = ++last_relay_session_id;
> + session->id = relayd_get_next_session_id();
> session->sock = cmd->sock;
> cmd->session = session;
>
> @@ -1032,7 +1033,7 @@ int relay_add_stream(struct lttcomm_relayd_hdr
> *recv_hdr,
> }
>
> rcu_read_lock();
> - stream->stream_handle = ++last_relay_stream_id;
> + stream->stream_handle = relayd_get_next_stream_id();
> stream->prev_seq = -1ULL;
> stream->session = session;
>
> --
> 1.7.10.4
>
>
> _______________________________________________
> lttng-dev mailing list
> [email protected]
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
_______________________________________________
lttng-dev mailing list
[email protected]
http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
